Only graphite pencil isn't always enough. At times color is needed. I have a two boxes full of colored pencils, all shades and sizes. Some are really small already since I have first used them as a child at school.
There are drawings mainly done with graphite but then for the fun of it a touch of color here and there. Yet at times it has to be far more colorful. Outdoor themes such as butterflies and flowers among others just need lots of color.
The challenge is shading to make it look realistic. And to exactly match the colors. To create highlights, change lighting and blend colors smoothly is key.
I am working in layers, lots of them. Bit by bit, applied in strokes with low pressure so the color can be removed easily to show more lighted areas. Needless to say this technique is far more timeconsuming. But the results can be stunning.